Preserved wood and process of making same.



UNITED STATES PATEN T OFFICE.

CARLETON EIIIS, MONTCLAIR, NEW JERSEY, ASSIGNOR '10 COPPER OIL PRODUCTS COMPANY, OF NEW YORK, N. Y.

PRESERVED WOOD AND .PROCESS OF MAKING SAME.

No Drawing.

To all whom it may concern:

Be it known that I, GARLETON ELLIS, a citizen of the United States, and a resident of Montclair, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Preserved Wood and Processes of Making Same, of which the following is a specification. I

This invention relates to a process of treating wood with preservatives and relates in particular to a method of injecting preservative material, such as sulfur-c0ntaining oils, creosote and the like, in a manner which preferably rovides the wood with merely a fiber coatlng of'the preservative solution.

It has been the custom heretofore to treat wood with creosote by what is known as the empty cell process which merely wet-s the fibers of the wood without introducing a saturating amount of the creosote oil. This reduces the cost of treatment without greatly reducing the preservative action.

Petroleum oils, and more particularly asphalt oils have been tried to some extent as wood preservatives. Among these are the so-called timber asphalt, Bakersfield asphalt and Mexican Ebano oil. Oils of this character are used in a saturating amountfor preserving wood, as for example railroad ties. The saturation of the tie calls for a large amount of oil and although the oil may be obtained near its source at a low cost per gallon in comparison to creosote yet the cost of saturating or full cell treatment of timber approximates that of creosote as applied in the empty cell process.

In the present invention oils of the creosote type may be used or mixtures of creosote oil and petroleum and asphalt oils, but the operation of the present process is more particularly intended for the treatment of wood with asphalt oils of rather heavy consistency containing sulfur or highpowered preservatives such as copper and arsenic compounds, dinitro benzol and the like.

As I have set forth in U. S. Patents No.

I 871,392 and 991,434 and in my copending the oil may be used advantageously for wood Specification of Letters Patent.

Application filed November 9, 1911.

Patented Mar. 19, 1912.

Serial No. 659,281.

preservation. Co per compounds of this character are use 111 for preserving certain classes of woods while other oil-soluble compounds such as those of arsenic, lead, mercury, zinc and the like are useful on other types of wood. The asphalt oils are very effective water-proofing materials and in this respect at least are superior to the creosote. As a rule they have a greater consistency than the creosote oils and hence are somewhat more difficult to introduce into the wood. Conversely itis also' somewhat difficult to remove from the wood any excess of the oil which may have been injected. These petroleum oils or residues have no pronounced antiseptic action and hence are not highly efficient preservatives. For example, they usually are not able to cope with Merulius lacrymans or dryrot, the mycelium of which secrete a considerable amount of a liquid substance, acting as a ferment and dissolving the fiber walls of some of the weaker cellulose structures and swelling and greatly weakening the harder varieties of cellulose tissues.

In addition to the high-powered preservative agents mentioned, certain other com; pounds of an-organic character, particularly the nitro-compounds of the aromatic series may be used. Among these are dinitrobenzol, dinitrochlorbenzol, dinitrophenol, dinitro ortho cresol and their homologues. Of these dinitrophenol is specially effective, its presence to the amount of 025% in nutrient gelatin preventing the growth of mold. Four (4) ounces of nitro-compound to a gallon of asphalt oil affords a very good preservative. 'One .(1) ounce of dinitrophenol and 1?; ounces of copper oleate' to a gallon of petroleum oil afi'ords an excellent tie preservative. In the case of preservatives to be used for treating piling to prevent the attack of tcredo and limnoria special pains must be taken to have the oil properly proportioned as regards the character and amount of the high-powered preservative. Dinitro ortho cresol in combination with oil-soluble arsenic compounds and copper oleate forms a useful basis for the treatment of piling. For wood which is not to be exposed to extreme service conditions and especially for railroad ties which are to be treated in such a manner that their preservative life substantially coincides with their mechanical life sulfur compounds are useful. It. has been proposed heretofore to make use of polysulfid of calcium for treatfriable oxycellulose.

ing wood. The polysulfidis partially converted into carbonate of lime and partly into thiosulfate and other oxysalts on eX- posure to the air. have an alkaline reaction and with the oxyen of the air convert cellulose into the This causes tendering of the wood and loss of spike holding power.

Sulfur forms a very goodantiseptic ma terial under some circumstances. The proposal made hitherto to impregnate wood with sulfur alone, in a molten state, has certain disadvantages, one of which is the high temperature required to put, the sulfur into a condition so fluid that it will penetrate readily. Another objection is" the rather brittle condition of the wood after the sulfur has-solidified, within its interstices. If however sulfur is dissolved by heating in an oil such as petroleum in which it is not very soluble at ordinary temperatures and the hot saturated solution introduced into wood, a portion of the sulfur will separate on cooling, forming a fine precipitate in and around the fibers of the wood.- In this state the sulfur is a good fungicide and greatly retards tributed throughout the interior of the wood;

At 120 degrees, the melting point of sulfur, ordinary petroleum oil takes up considerably more than 10% of sulfur. With asphalt oils and other unsaturated oils,

union of sulfur and oil takes place, more'or less, at 120 degrees C. and-the oil becomes vulcanized, usually accompanied by thickening. A vulcanized asphalt oil, containing uncombined sulfur, may readily be thinned with creosote; twenty five or thirty per cent. of the latter sometimes being required. \Vhen'creosote and petroleum oil are mixed it has been supposed that the bactericidal qualities of the creosote were greatly'diminished or entirely suppressed by the palliative efiect of the petroleum oil. This is not however strictly true. Petroleum has relatively slight antiseptic action and dilu-.

. tion of the creosote by it perhaps reduces the preservative action to an extent slightly greater than the degree of dilution would warrant. On the other hand creosote as compared to some of the petroleum oils and Some of these compounds particularly the partially. Vulcanized asphaltic oils, is a poor waterproofing agent.

An oil which thoroughly Waterproofs is a I great desideratum in wood preservation, hence the combinatlon of creosote and partially vulcanized asphaltic oil fortified with an excess of uncombined sulfur ofiers a preservative having a number of valuable quali ties. By adjusting the ratio of creosote and asphalt oil for each particular wood the requisite penetration and waterproofing, qualities are secured. The antiseptic features of creosote are supplemented by the fungo-toxic action of the precipitated interstitial sulfur, the amount of which is under regulable control, and the precipitation of sulfur in the pores of the wood tends to augment the resistanceof the wood to the penetration of moisture. The asphalt oil obtained from the Bakersfield region is remarkably eifective as a waterproofing agent'but the supply of this useful oil is limited. The vulcanization of ordinary petroleum residues and semi-as phaltic oils affords a substitute for the Bakersfield oil at a very moderate cost.- Such a vulcanized oil can be properly fortified with a high-powered antiseptic to form a satisfactory preservative. sulfur over that required for vulcanization By using an excess of at any specific temperature the excess of the sulfur serves as an antiseptic and affords an oil which is very serviceable in many localities. Creosote may be used in the form of a .miscible oil. potash and introduced into creosote the mixture may be diluted with water-to a Very considerable degree and still persist as a clear homogeneous solution. On the furtheraddition of water however the creosote 105 is precipitated and forms a milky emulsion.

. Such mixtures as these may carry petroleum or asphalt oils and may be introduced into 3 wood at such a dilution that the further addition of water causes precipitation of the creosote.

A copperized miscible oil may be made in accordance with Letters Patent on miscible oil, No. 993,827.

Thus when the tie or other cellulose structure treated in this way is exposed to-rain or earth moisture the creosote'or other oily body precipitates and dc: posits on the wood fiber.

taken in the case of green or unseasoned' Care should be wood, as a moisture sensitive solution of this character would cause precipitation of the creosote or other oil, during the impreg nating process. Seasoned wood is far more adaptable to this treatment than green mois ture containing'wood. Of course it is not desirable to have a strongly alkaline soap present in large amount, because of liability of oxidation of the cellulose to oxycellulose. Rosin soap is somewhat inclined to alkalinity becauseof hydrolysis and is best used in conjunction with a small proportion of If rosin is saponified with the particles of oil of the emulsion on the surface of the timber. Anhydrous zinc chlorid or zinc fluorid may be dissolved under certain condition in asphalt oils to some extent to secure a moderately good anti-Q septic material. Timber treated with miscible oil containing water-soluble soap may be immersed in a solution of calcium chlorid, magnesium sulfate, barium chlorid, copper sulfate and the like so as to form a metallic water-insoluble soap in the superficial pores of the timber, thereby improving its resistance to the entry of moisture. The precipitation of the soap renders the oil vehicle of the miscible oil no. longer soluble with water thus causing said oil vehicle to become fixed. Creosote solutions which are soluble inwater may also be made by use of, sulfonated oils. The manner in which compositions of this sort may be prepared has been set forth in Patent 879,375. Simply mixing a slightly alkaline concentrated sulfonated oil with creosote yields a useful product.

The copper and other compounds of naphthenic acids are useful with a certain limited number of oils for treatment of wood. Copper naphthenate is a very effective preservative. If present to the extent of 1% it prevents the development of the lower organisms. 1% or 2% of copper naphthenate in solution in gasolene is absorbed by dry wood readily, although so low a proportion of nonvolatile material does 'not waterproof the wood. If however copper naphthenate' is dissolved in fairly heavy Texas or Oklahoma asphalt oil a waterproofing and preservative composition is secured.

In carrying out. the process of the present invention the compositions described in the foregoing may be used. In certain modifications, of the process involving low impregnating temperatures, the sulfur and oil solution mentioned above is not asreadily used.

For im regnation, I preferably employ wood whic has been air or kiln dried. The treatment of green wood to remove the moisture by means of hot creosote oil for example, is undesirable because of' the tendency to thereby weaken the fiber. Creosote combines toa certain'extent with wood fiber, especially if heated to a high tem say 130 to 150 degrees F., are to be preferred to 212 degrees F. The present process embraces the treatment of wood with a preservative oil to cause partial impregnation,

the wood used for these purposes being preferably previously dried so that moisture is not expelled to the detriment of the operation and in subjecting the partially impregnated wood to a very high gaseous pressure to properly distribute the oil I prefer a gas substantially free from or of reduced oxygen content to be used. The subjection of heated wood whose surfaces are coated with oil to ordinary air until high pressure carries with it the tendency to spontaneous ignition, which is avoided by the preferred procedure herein set forth.

In carrying out the process I preferably use two impregnating cylinders and pass the gas from one cylinder to the other, to

and fro, alternating the operations so the gas may be used over and over again. and in such a manner that it does not have to be compressed from atmospheric pressure up to the maximum pressure required each time a charge is applied, in accordance with the process of Serial No. 638,600%.

In the present invention the treatment.

of wood which is to be subjected to great mechanical stress such as aving blocks, railroad ties and the like, it is especially an objective to apply a preservative whose specific preservative action is carefully regulated to endure for a period substantially that of the mechanical life of the fibrous structure. Creosote may be and is used in possesses two important features, namely,

fluidity at high temperatures with consequent ease'of impregnation; and a desirable degree of viscosity at low temperatures,

which secures waterproof or water resistant qualities in a high degree. There is the further advantage of treating of these sulfurized oils, that they may be caused to oxidize and dry in the superficial layers of .ufacture from low grade petroleum oils,

with the preservation of wood because of its -with oil in such a manner that the'heat of type.

the. fiber coating of railroad ties, paving blocks and the like, adjusting the amount of life substantially coincide.

large extent, of the Bakersfield oil.

- asphaltic oil.

the fibrous structure, so that the oil in the interior of the structure is fairly within the wood. This is important, especially in making paving blocks which may be charged thesun does not cause the liquid to exude from the interior of the block, a defect which has heretofore been observed in many of the compositions of the creosote and resin The present invention contemplates also oil to this end and proportioning the amount of high power antiseptic material with respect to the mechanical life of the railroad tie or other fibrous structure whereby the preservative life or action and mechanical The treatment of petroleum. oils with sulfur, with or without the induction of oil soluble copper or arsenic salts or other high power preservative, makes possible the manan oil which has the properties, to a very The supply of the latter is not very great, but it is in considerable demand, in connection good waterproofing qualities, and the present invention especially is. concerned with the conversion of low grade petroleum oils by sulfur treatment and the like, thereby producing an oil which has an even better waterproofing character than Bakersfield 'What-Tclaimis: v

1. The herein described process of preserving railroad ties and other fibrous ma-j terial consisting in injecting thereinto at 'K v oa ers least a fiber-coating amount of a vulcanized asphalt oil carrying antiseptic material, the said antiseptic material being present in a predetermined amount, whereby the preservative action substantially coincides with the life of the tie, and in causing at least a major portion of the interior fibers of said tie or other fibrous material to be coated with said oil,

2, The process of treating wood comprising subjecting same to a vulcanized .asphalt oil under pressure, said oil containing an 5. As a new article of manufacture wood impregnated with an oily medium comprising vulcanized asphalt oilv carrying an excess of sulfur.

. 6. As a new article of manufacture wood impregnated with'an 'oily medium comprising artificially vulcanized petroleum oilcarrying an excess of sulfur.

7. As a new article of manufacture wood carrying artificially vulcanized petroleum oil.

Signed at 'Montclair in the county of Essex and State of New Jerseythis 4th day of 75 November A. D. 1911.

1 CARLETON ELLIS.

Witnesses: 'CHARLI }S WRIGHT,

WALTER O. BLADEN. 

